1. Field of the Invention
The present invention relates to a photosensitive composition and, more particularly, to a photosensitive composition photosensitive to deep UV light.
2. Description of the Related Art
In recent years, a demand has arisen for high-density integration for realizing multifunctional high-density electronic equipment, and finer patterns to be formed in electronic parts have been required accordingly.
In the manufacture of electronic parts such as semiconductor ICs requiring various types of micropatterning techniques, a photosensitive resin is widely used in formation of fine patterns. As an exposure apparatus for use in formation of patterns using a photosensitive resin, a step-and-repeat reduction-projecting type mask aligner called a stepper is conventionally known. Examples of light for use in such an apparatus are g rays (wavelength =436 nm), h rays (wavelength =405 nm), and i rays (wavelength =365 nm) of a mercury lamp, and XeF (wavelength =351 nm), XeCl (wavelength =308 nm), KrF (wavelength =248 nm), KrCl (wavelength =222 nm), ArF (wavelength =193 nm), and F.sub.2 (wavelength =157 nm) of an excimer laser. In order to form fine patterns, the wavelength of light to be used is preferably short. Therefore, a demand has arisen for a resist sensitive to deep UV light such as an excimer laser.
A conventional known example of a photosensitive resin photosensitive to an excimer laser is a photosensitive composition consisting of an acryl-based polymer such as polymethylmethacrylate (PMMA) or polyglutarmaleimide (PGMI) or a polymer having phenol and an azide-based photosensitizing agent. A photosensitive composition using the former polymer, however, dry etching resistance. Although a photosensitive composition using the latter polymer has high sensitivity and a high dry etching resistance, a sectional shape of a pattern formed by using this photosensitive composition becomes an inverted triangle. Therefore, there is a problem that it is difficult to control exposure and development steps.